A week later, Renner went on a rant about the incident at In Style's Golden Globe party after seeing Aguilera at the fete.

"Someone comes and tells me she's in my room," he told pals at the Jan. 16 affair. "I run up and open the door and I'm like, 'Um, hi. What are you doing?' She just starts slurring. Her boyfriend [Matthew Rutler] was rubbing her back. Who comes to someone's birthday party that they don't know and gets in their bed?! My parents were there!"

Adds another source, "Christina was a mess at that party. She acted like a fool. Her boyfriend was shushing her and telling her to go to sleep."

(Renner's rep says that Aguilera "was enjoying herself, but she wasn't in his bed.")